| Congresso Brasileiro de Microbiologia 2023 | Resumo: 967-1 | ||||
Resumo:Microorganisms play a central role in the marine biogeochemical cycles. The ammonia-oxidizing archaea, a chemolithoautotrophic group composed of several taxa from the class Nitrososphaeria, can perform out the first step of nitrification while fixing inorganic carbon, making them important players in the nitrogen and carbon cycles. Recent studies have indicated the importance of these organisms to the marine environment, but our knowledge is still very limited, with scarce information available about of the diversity and ecology of the group in the Southwest Atlantic Ocean. The ammonia-oxidizing archaea in the Santos Basin (South West Atlantic) were studied using molecular approaches as part of the Santos Project – Santos Basin Environmental Characterization (Brazil), coordinated by PETROBRAS/CENPES, an energy company, and National Agency for Petroleum, Natural Gas and Biofuels (ANP), in collaboration with Institute Oceanographic of the University of Sao Paulo (IO-USP). A compositional dataset of the V4 region of the 16S rRNA enabled to evaluate the diversity and distribution of the ammonia-oxidizing archaea from 94 sediment and 175 water samples from neritic and oceanic zones of the basin. Nitrososphaeria accounted for up to 50% and 20% of the communities in sediment and water samples, respectively. The Nitrosopumilales order had the highest richness, diversity, and abundance indices in the slope region of marine sediment. Temperature, salinity, and depth were environmental factors that shape the community structure of Nitrosopumilales in the sediment. Nitrosopumilales order had the highest richness, diversity, and abundance indices in the water column from the mesopelagic zone. Temperature, dissolved oxygen, and nitrate were environmental factors associated with the community structure of Nitrosopumilales in the water. This result showed that, on an oceanic regional scale, temperature plays an important role in the structure of the ammonia-oxidizing archaea community in the sediment and water column. This finding implies that changes in ocean temperatures have the potential to modify the distribution of the group in the ocean. Palavras-chave: Nitrososphaeria, nitrogen, biogeochemical cycles, molecular analysis, Santos Basin Agência de fomento:Fundação de apoio à Universidade de São Paulo (FUSP) | |||||